diff options
| author | Vincent Whitchurch | 2021-12-10 17:09:51 +0100 |
|---|---|---|
| committer | Alexandre Belloni | 2022-02-15 23:06:19 +0100 |
| commit | c8fa17d9f08a448184f03d352145099b5beb618e (patch) | |
| tree | 7ab52c445a6b8b15b360096baec9c1509272bbb3 | |
| parent | e783362eb54cd99b2cac8b3a9aeac942e6f6ac07 (diff) | |
rtc: fix use-after-free on device removal
If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work(). Cleanup the
timerqueue and ensure the work is stopped to fix this.
BUG: KASAN: use-after-free in mutex_lock+0x94/0x110
Write of size 8 at addr ffffff801d846338 by task kworker/3:1/41
Workqueue: events rtc_timer_do_work
Call trace:
mutex_lock+0x94/0x110
rtc_timer_do_work+0xec/0x630
process_one_work+0x5fc/0x1344
...
Allocated by task 551:
kmem_cache_alloc_trace+0x384/0x6e0
devm_rtc_allocate_device+0xf0/0x574
devm_rtc_device_register+0x2c/0x12c
...
Freed by task 572:
kfree+0x114/0x4d0
rtc_device_release+0x64/0x80
device_release+0x8c/0x1f4
kobject_put+0x1c4/0x4b0
put_device+0x20/0x30
devm_rtc_release_device+0x1c/0x30
devm_action_release+0x54/0x90
release_nodes+0x124/0x310
devres_release_group+0x170/0x240
i2c_device_remove+0xd8/0x314
...
Last potentially related work creation:
insert_work+0x5c/0x330
queue_work_on+0xcc/0x154
rtc_set_time+0x188/0x5bc
rtc_dev_ioctl+0x2ac/0xbd0
...
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210160951.7718-1-vincent.whitchurch@axis.com
| -rw-r--r-- | drivers/rtc/class.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 4b460c61f1d8..40d504dac1a9 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -26,6 +26,15 @@ struct class *rtc_class; static void rtc_device_release(struct device *dev) { struct rtc_device *rtc = to_rtc_device(dev); + struct timerqueue_head *head = &rtc->timerqueue; + struct timerqueue_node *node; + + mutex_lock(&rtc->ops_lock); + while ((node = timerqueue_getnext(head))) + timerqueue_del(head, node); + mutex_unlock(&rtc->ops_lock); + + cancel_work_sync(&rtc->irqwork); ida_simple_remove(&rtc_ida, rtc->id); mutex_destroy(&rtc->ops_lock); |